1. Field of the Invention
The present invention relates to the field of manufacturing storage devices and, more particularly, to quartz tube storage devices.
2. Prior Art
In the manufacture of silicon based semiconductor integrated circuit devices, various circuit elements are formed in or on a base silicon substrate. Generally, the process of forming these various circuit elements starts from a base silicon wafer, which is typically flat and is circular in shape. On each of these flat circular wafers a number of integrated circuit devices, typically known as "chips" are formed by the use of various well-known techniques, including photolithography, doping, depositing, etching, and annealing techniques, just to name a few.
The silicon wafers are typically formed, stored and processed in elongated glass-type containers commonly referred to as quartz ware or quartz tubes. These quartz containers are utilized primarily due to the high temperatures encountered in the furnaces for processing silicon wafers and the ability of these containers to withstand such high temperatures.
These tubes are typically stored horizontally in racks or in PVC pipes, or they are stored vertically, side-by-side, in cabinets or in racks. However, such storage schemes currently in practice require considerable floor space or present difficulty in handling the containers. For example, horizontal storage requires floor space at least as long as the containers themselves. If PVC piping is used for storage, additional floor space is required to allow the tubes to be pulled out of the PVC piping. If vertical storage is used, any stacking will present a problem in accessing a given tube.
As an additional example, six typical quartz tubes 13 inches in diameter and 9 feet long, would if stored horizontally, take floor space approximately 30 in..times. 18 ft. Storing tubes vertically side-by-side in a cabinet or a rack will use approximately 18 in. deep.times. 7 ft. long. Where ample space is available for storage of these tubes, floor space consideration is not a concern. However, in the highly controlled clean room environment of semiconductor fabrication, floor space usage is always a paramount concern.
It is appreciated then that a need exists for a device to store quartz tubes in an easily accessible manner and reduce the floor space requirement for such storage.